21) A Rulebook for Arguments, by Anthony Weston
22) Critical Reasoning: An Introduction, by Anne Thomson

Got these just to see if my science degree had seriously impacted my ability to construct sensible arguments. I seem to have picked up the necessary skills along the way somehow, though, despite not writing any essays between my desultory first-year geology course and my final-year dissertation on the origin of the universe. Still, two quite nice little books: the first more for Americans, and just containing rules to follow; the second for the British market, containing some interesting examples to work through. Well, more fun thatn Sudoku anyway.